Going up my first Alp in 3 weeks, its an 11k 6% hill, and having rarely gone out on the bike in the last 2 months its evident that I’ll struggle

Curently I’m running a compact up front with a 28 tooth out back, which is fine for any riding I do at home, but I know that theres no way I’ll be able to spin myself up in that gear. Now thinking th best option is a far bigger rear cassette, but don’t know what my options are.

I currently run 11 speed ultegra, with the biggest rear cog suggested being 28 tooth. Given I won’t be using the full range of gears on the climb, how big a rear cog can I get away with on an ultegra rear mech, taking into account I’ll never be in the large chainring, nor will I be going anywhere near the top half of the cassette.

And failing that, can I swap my 11 speed xt mech over from the mtb and use the 42 tooth casstte from that? (I do realise the frenchies will look at me in disgust if I do this)

I also appreciate anyone as unfit as me shouldn’t be going anywhere near an alp, but its to see the penltimate tour stage, and has been planned for ages.

Just go with what you’ve got on your road bike…..you’ll be fine 🙂

34 – 28 on 6% is reasonable.

11sp road and mtb are not compatible.

You could get a GS cage 105 mech and 11-32 cassette. That would be the cheapest way to give yourself super-easy gears. 34 – 32 is really low.

I run 11-32 cassette on my full Ultegra 6800 set up. It’s what comes as standard on trek domane and silque.

You know there are lifts yeah?

It’s what comes as standard on trek domane and silque.

There are 2 versions of the rear mech SS (short cage) and GS (medium cage). The SS takes up to 28 cog, and the GS takes up to 32.

Just take your time. The hill isn’t going anywhere. Stop and take pictures, maybe have something to eat. You’ll get up it.
Enjoy coming down, because you’ll have ridden up it.

I agree with Splashdown, go with what you’ve got. Riding an alpine climb is rarely easy, but is probably easier than you think. I generally find the first km quite tough going, until I get into a rhythm, once in a rhythm it all starts to feel manageable. Especially if there aren’t any sections that get ridiculously steep. It’s not like trying to honk up a short but steep climb in this country.

Work out what time of the day the sun is on the climb and avoid that time. If it is in the sun all day then set out early.

Oh and it seems silly, take a gilet/jacket/arm warmers for the descent. Even on hot days descending at speed can feel cold after you’ve been sweating for so long.

Yeah go with what you got.
I struggled a couple of years ago checked the cassette it was a 11/25 28 makes it all rideable.

Pace is key on alpine climbs, take it easier than you think you should to sustain it for 11km. It’ll actually be easier than you think at 6% and gearing will be just fine. If there are steeper sections then change down gears don’t waste energy trying to honk up, and if there are any hairpins or flatter spots then use it to ease up a bit – avoid wasting energy! Drink little and often if its hot. Take in the magnificent views and enjoy the achievement.

11sp road and mtb are not compatible.

Wrong – or at least they can be – Here – changes the pull ratios to make running a mtb cassette with road shifter possible – works a treat and available for about £30 form 18bikes

it really helps that they they have 1km markers to the summit, at least they did have in the PDS region.

Half the battle is your head, your brain will give up first, find a gear you can spin with, chill out and switch off and enjoy the ride, good luck

Wrong …*snip* … available for about £30 form 18bikes

So, more expensive than buying a long cage 11sp road mech. 😉

would a 32 work without a new mech if i stay in the small chainring at all times?

Not sure. I think the parallelogram geometry must be slightly different (as well as the cage length), as the reason there is a max cog size is due to the top jockey wheel fouling the cassette. You might be able to wind-out the b-tension screw. Or you might not. It depends on your frame and mech hanger position.

It appears it might work.

https://www.youtube.com/watch?v=biB-pkdoXSw

So, more expensive than buying a long cage 11sp road mech.

Correct, but you can’t run a 36/40t cassette with a double on an 11s road rear mech…

36 looks possible

https://www.youtube.com/watch?v=T9q4WpaqwgI

Not sure what you’d be riding up to need a 40 on a road bike. But I agree, that would need an MTB mech. 🙂

I’d just stick with what you have.
11km is not that long, and 6% is not that steep, and its only 1 hill, not a whole day riding hills.
You should also note that 6% on freshly laid TDF roads will feel more like 4% on UK roads.

Slicks on your mountain bike? 😆

I switched to a 12-30 cassette and a compact for a big day out in the Alps – it did allow me to carry on spinning when I was knackered, but I tend to keep a higher cadence than most. 11-28 is hardly any different so I’d stick with it. As others have said, take breaks and enjoy the scenery -it’s not a race.

And yes, I’d say a windproof is essential for the descent, as you’ll be soaked in sweat from the climb.

will be hanging about the top for a few hours to watch the tour pass, so hopefully have cooled off by then

now all i need is a way to transport my beer up beforehand

which one are you cycling up?

Slicks on your mountain bike?

and why not….

mate & I did a short alps tour a couple of years back, on one pass we caught up with a french guy on an mtb who’d just cycled from northern france & had only got round to sticking slicks on it after the first two weeks of his tour, he was also towing a trailer, still enjoying himself & still riding to the top. We were on what people round here lovingly refer to as hybrids – flat bars & triples – perfect for the job & don’t have to worry about changing cassettes just to get over a few lumps 🙂

the only alp I’ve ever climber up was after the train to chamonix never arrived and I was faced with a 11k climb back up to chatel, on my spesh enduro with supertackies, full facer and body armour..plus I had a cold. What I would have given for a road bike with 34/28 then! I am stone cold last of about 400 folks that have done it on strava…most miserable day of my life!

Don’t have slicks for my MTB so prob as cheap getting a new cassette. I think I’ll chance a 32 tooth which I can get for around 25 quid.

I’m climbing up the last descent on the penultimate day of the tour (no idea what its called – its from morzine). Its an mtb holiday, but the chance to see the tour for the first time is to good to miss so chucking the road bike in the car as well.

Anyone else going to be there?

First time I did Alpe d’Huez I had slicks on my (26er) mtb, and a backpack. No big deal!

The climb up the backside of the Joux-Plane isn’t so outrageous, certainly easier than the way they’ll be riding up, and its only about 700m vertical 🙂

If you are climbing to the top then hanging around for a few hours then definitely climb with a windproof/gilet/arm warmers. Even red hot days can get cool quickly. We were out for the Tour last year, lots of mid afternoon thunderstorms cooled things down a little and the rain was very heavy. Best to be safe.

You could take a little bag up too so that you can carry Tour caravan booty home. Although draw string bags and bags for life seemed to be a staple give away last year.

Four of us off to Ventoux in a couple of weeks, hope to go up before the tour, on Bastille day! Training has gone to shit after a fractured arm and now a cold. Can’t wait.